Acid resistant alloys

ABSTRACT

An acid resisting alloy consisting essentially of about 10 to 50 percent titanium, 50 to 85 percent columbium, 5 to 10 percent tungsten, and 0.5 to 3 percent zirconium.

1 Apr. 9, 1974 ACID RESISTANT ALLOYS [75] Inventor: Maharaj K. Koul, Lewiston, NY.

[73] Assignee: Union Carbide Corporation, New

York, NY.

[22] Filed: Jan. 15, 1973 [21] Appl. N0.: 323,787

Related US. Application Data 1 gnt nuati tulw No- 31A 920815151919,

abandoned.

[52] US. Cl. 75/174, 75/175.5 [51] Int. Cl C22c 27/00 [58] Field of Search 75/174, 175.5, 134 N [56] References Cited UNITED STATES PATENTS 2,822,268 2/1958 Hix 75/174 3,317,314 5/1967 Wlodek et a1. 75/174 FOREIGN PATENTS OR APPLICATIONS 803,855 1 1/1958 Great Britain 889,099 2/1962 Great Britain 925,107 5/1963 Great Britain Primary Examiner-Hyland Bizot Assistant Examiner-E. L. Weise Attorney, Agent, or Firm-Frederick J. McCarthy, Jr.

[ 5 7 ABSTRACT An acid resisting alloy consisting essentially of about 10 to 50 percent titanium, 50 to 85 percent columbium, 5 to 10 percent tungsten, and 0.5 to 3 percent zirconium.

1 Claim, No Drawings ACID RESISTANT ALLOYS This is a continuation, of application Ser. No. 080,812 filed Oct. 14, 1970 now abandoned.

This invention relates to acid resistant alloys. More particularly this invention relates to titanium containing alloys which are resistant to oxidizing as well as reducing media. While alloys are known which are resistant to either oxidizing acids such as nitric acid or reducing acids such as hydrochloric acid at present there is no known material which is resistant to hot concentrated reducing and oxidizing acids. Such an alloy would be highly useful for applications in the chemical industry such as autoclaves, seals and acid tanks.

It is therefore an object of the present invention to provide an alloy which is highly resistant to both oxidizing and reducing media.

Other objects will be apparent from the following description and claims.

An alloy in accordance with the present invention consists essentially of from about 10 to 50 percent titanium, 50 to 85 percent columbium, to percent tungsten and 0.5 to 3 percent zirconium. A preferred alloy in accordance with the present invention is one containing about 26 percent titanium, 65 percent columbium, 7.5 percent tungsten and 1.5 percent zirconium,

Alloys in accordance with the present invention are readily melted by vacuum arc melting techniques and can be readily fabricated into industrially useful forms such as sheet, plate and the like.

The following examples will further illustrate the present invention.

EXAMPLE I Alloy test specimens having a composition of 26% Ti, 65 percent Cb, 7.5 percent W and 1.5 percent Zr in the form of 1 inch X 1 inch X 0.03 inch sheet samples were tested in percent HCl at 70C, boiling H2504 (40 percent), and boiling 65 percent nitric acid. Similarly sized test specimens of an alloy having a composition of Ti, 0.2 percent Pd were also tested in the same manner. The results of the tests are shown in Table I.

Table I Alloy Composition wt% Test Media Corrosion Rate in/year 26% Ti, 65% Cb, 65% HNO; Nil 7.5% W and 1.5% Zr (Boiling) 20% HCl .001 (70C) 40% 11,80, .02 (Boiling) Ti0.2% Pd. 65% HNO .025

(Boiling) 20% HCl .010 (70C) 40% H,S0 2.2 (Boiling) EXAMPLE 11 Alloy test specimens having a composition of 26 percent Ti, 65 percent Cb, 7.5 percent W and 1.5 percent Zr in the form of 1 inch X 1 inch X 0.03 inch were tested by exposure to the off-gas condensate from a vanadium salt roast process at a temperature of 90- 100C The off-gas condensate contained approximately 17 percent HCl and 1.5 percent HF.

Test specimens in the form of 1 inch X 1 inch X 0.03 inch sheet samples of alloys having compositions of Ti 0.2 percent Pd and Ti 26 percent Mo were also tested in the off-gas condensate. The results are shown in Table I1. 7

1. An alloy of titanium, columbium, tungsten and zirconium resistant to hot oxidizing and reducing acids consisting essentially of about 26 percent titanium, 65 percent columbium, 7.5 percent tungsten, and 1.5 percent zirconium. 

